Technical Field
Embodiments of the invention relate generally to electronic signal monitoring and more specifically to methods for analyzing noise in an electrophysiology study.
Discussion of Art
Electrocardiography (ECG) studies record the electrical activity and pathways of a heart to identify, measure and diagnose arrhythmias. To accomplish this, ECGs utilize electrodes that are combined into pairs, the output of which are referred to as a lead. ECG leads are used in electrophysiology (EP) studies, which assess electrical activity through the use of catheters placed in the heart through veins or arteries. More specifically, surface ECG leads attached to the patient are used as the reference for the intra cardiac signals from the catheters. That is, they apply a voltage reference to the patient for measurement by other leads.
In the electrophysiology context, ECG and intra cardiac leads may encounter line frequency noise, magnetic noise and/or noise from muscle tremor. Study noise may result from the use of wireless electrical devices, ablation equipment, the attachment of multiple medical devices to a subject, ungrounded electrical extension cords, electrical sockets, high-energy consumption equipment, and the like. In addition, the leads have to measure relatively small electrical signals from the patient, less than 20 uV in some instances. As will be appreciated, given the above considerations, achieving acceptable study recordings may be challenging and eliminating/reducing study noise is an important consideration.
In view of the above, it is desirable to accurately and efficiently identify sources of noise, and quantify the effects of noise, in electronic signal monitoring studies such as EP studies and the like, so that the sources may be removed.